Aromatic polycarbonates are well known polymers having excellent impact resistance, toughness, electrical properties and dimensional strength. However, aromatic polycarbonates resistance to various solvents is not as high as desired. Of particular concern is the aromatic polycarbonate resistance to basic solvents such as those containing ionic or ionic like hydroxyl, basic alcohols and amines. Basic substances are known to attack the carbonate bond, thereby forming oligomers out of the polymeric resin with a concomitant decrease in such properties as impact strength.
The admixing of aromatic polycarbonate with other polymers is generally done to upgrade certain properties of aromatic polycarbonate. Because of their great strength to weight ratio, as well as upgrading of polycarbonate properties, aromatic polycarbonate admixtures have extended the application of aromatic polycarbonates to other potential fields, particularly automotive, and the like. Various upgrading of properties can be done to provide a molded part suitable for a new application. For example, a part made for use in or near the engine compartment should maintain good properties at high temperature. Environmental exposure, for example resistance to gasoline, can be very significant for a bumper made from plastic admixtures. Often the upgrading of one property by the addition of a single polymeric component may cause no further upgrading of other properties or may actually lower the values of other properties. Thus, the addition of a third component is sometimes necessary.
It has now been found that an aromatic polycarbonate containing composition can have substantially increased thick section impact in comparison to polycarbonate alone, good processing characteristics, and good compatibility as measured by impact resistance along a weld line while retaining virtually all of its impact resistance after exposure to a basic organic solution.